Convert the until/advance commands to thread_fsm mechanism

Convert the until/advance commands to thread_fsm mechanism

gdb/ChangeLog:
2015-09-09  Pedro Alves  <palves@redhat.com>

	* breakpoint.c: Include "thread-fsm.h".
	(struct until_break_command_continuation_args): Delete.
	(struct until_break_fsm): New.
	(until_break_fsm_ops): New global.
	(new_until_break_fsm, until_break_fsm_should_stop): New functions.
	(until_break_command_continuation): Delete.
	(until_break_fsm_clean_up): New function.
	(until_break_fsm_async_reply_reason): New function.
	(until_break_command): Adjust to create an until_break_fsm instead
	of a continuation.
	(momentary_bkpt_print_it): No longer print MI's async-stop-reason
	here.
	* infcmd.c (struct until_next_fsm): New.
	(until_next_fsm_ops): New global.
	(new_until_next_fsm, until_next_fsm_should_stop): New function.
	(until_next_continuation): Delete.
	(until_next_fsm_clean_up, until_next_fsm_async_reply_reason): New
	functions.
	(until_next_command): Adjust to create a new until_next_fsm
	instead of a continuation.